1. Field
The following description relates to a centralized radio access network (C-RAN).
2. Description of the Related Art
A centralized radio access network (C-RAN) has a structure, where a digital unit (DU) in charge of digital signal processing of a base station and resource controlling is integrated into one station in the form of a centralized station, and where a radio unit (RU) in charge of a passive function of amplifying a radio wave signal and transmitting it to an antenna is connected remotely to the DU through an optical cable. A trend of a recent high-speed mobile communication network is a C-RAN system, in which a base station is separated in to a DU and an RU, and the DU is changed to cloud. A signal transmission section between the DU and the RU in C-RAN is called a mobile fronthaul, and as a method of transmitting an optical signal in this section, intermediate frequency over fiber (IFoF) analog optical transmission method, which has a simple structure and is cost-effective, is being mentioned as a technical candidate to implement the mobile fronthaul of C-RAN.